Comment

Representation ID: 15844

Received: 11/05/2016

Respondent: National Highways

Urban extensions:
The most significant urban extension involves 500 dwellings at Shenfield close to the A12 junction. A further 250 dwellings are expected near Doddinghurst Road in North Brentwood. There is no easy access to the A12 from the sites in North Brentwood.

Comment

Representation ID: 15846

Received: 11/05/2016

Respondent: National Highways

Employment
The most significant employment site (shown as a purple dot in the south west of Figure 1) is Site 101A at Cobham Hall to the east of M25 Junction 29. The only access and egress is via Junction 29. The location of this site in the extreme south west of the borough and its proximity to the motorway means that many of the trips will originate from outside of the borough.

Comment

Representation ID: 15848

Received: 11/05/2016

Respondent: National Highways

Strategic housing:
2500 dwellings at Dunton Hills Garden Village (shown as a red dot in the extreme south east of Figure 1);
2500 dwellings at sites in West Horndon (shown as blue dots in the south of Figure 1);
1170 dwellings at sites in North Brentwood (shown as green dots in the north of Figure 1); or
1000 dwellings at Running Waters (shown as an orange dot in the centre of Figure 1).
The strategic sites involve significantly more concentrated development than the brownfield sites and are generally larger than the urban extensions. AECOM understand that Option 1 has been taken forward for inclusion within the LP.

Comment

Representation ID: 15849

Received: 11/05/2016

Respondent: National Highways

A total of 23 junction have been modelled. None of the Strategic Road Network junctions have been modelled. Base year turning counts have been undertaken at these junctions. Although modelling has not been undertaken at either of the motorway junctions, the forecast increase in traffic at these
junctions is higher than at any other junction. With the exception of the motorway junctions, nearly all of the significant junctions which are affected by forecast development flows are included. Notable exceptions are the two left-in left-out junctions located between junctions 14 and 19/20 on the A127.
Roundabouts and priority junctions have been modelled using JUNCTIONS 8 software. LINSIG has been used for modelling signalised junctions. With the exception of Junctions 15 and 16, which are treated as a double mini-roundabout, no consideration is taken of potential interference between the junctions. This is only likely to be an issue for those closely-spaced junctions in the centre of Brentwood.

Comment

Representation ID: 15850

Received: 11/05/2016

Respondent: National Highways

Trip generation: The residents per household and person trip rates were from acceptable sources although trip rates appeared to be "quite low".
Noted that TRICS will give trip rates for a typical not an average day , in terms of junction assessments, "a typical day may be more appropriate".

Comment

Representation ID: 15851

Received: 11/05/2016

Respondent: National Highways

Trip distribution: For work trips, a matrix of weights was calculated using distance weights derived from Census journey to work data. In principle, this is reasonable.
Education trips used a matrix of weights using schools as attractors. This is considered to be acceptable.

Comment

Representation ID: 15852

Received: 11/05/2016

Respondent: National Highways

Assignment:
It was recognised that this method of assigning development trips would result in one route being used between each zone pair. In addition, there should be no reassignment of existing trips to avoid increasing congestion resulting from the assignment of development trips. PBA considered that this would represent a worst case for congestion. This could be the case for the junctions on routes used by development traffic. It could underestimate traffic at junctions which would be affected by reassigning traffic and junctions on other routes which would be expected to be used between certain zone pairs.

Comment

Representation ID: 15853

Received: 11/05/2016

Respondent: National Highways

Strategic Housing Developments
Dunton Hills Garden Village
Plots are shown of flows from four development options in Appendices C and D of the PBA report. It is stated that these are exclusive of the baseline traffic flows. However, the plots appear to show more traffic on the M25 than that coming from the developments. The mechanism for excluding this traffic is not known. Hence, there is some doubt that the plots are entirely accurate.
AECOM therefore consider that the assessment of the impact of Option 1 on the M25 junctions could be considered broadly robust. However, if a higher proportion of trips travelling to destinations east on the A12 travelled through the town centre and accessed the A12 at Junction 12, there could be a greater number of turning movements at that junction than is predicted by PBA.

Comment

Representation ID: 15861

Received: 11/05/2016

Respondent: National Highways

North of Brentwood strategic option
Whilst AECOM recognise that the assignment of trips via the M25 rather than the A128 may underestimate the number of trips on the local highway network, AECOM consider that by assigning a significant proportion of traffic via the M25, this should result in a robust assessment of the impact of options three on Junction 28. However, if traffic routed via A1023, for access to the SRN for trips travelling along the A12 to / from the east the first point of contact could be at A12 Junction 12. Therefore, by assigning the majority of these trips via M25 Junction 28 the modelling could be underestimating the impact of turning movements at A12 Junction 12.

Comment

Representation ID: 15864

Received: 11/05/2016

Respondent: National Highways

Strategic option - East of running waters
This site is at a greater distance from the major roads than the other alternative options considered. Trips disperse via the A128, The Avenue and Running Waters. The choice of road used to travel to and from the A127 in the AM and PM peak differs. The choice of route makes a significant difference to the junctions used. In reality, there is likely to be a split with some relief for the most congested junctions but increases at less congested junctions.
Despite the distance of the strategic site option four from the SRN, there is predicted to be an increase in trips at both M25 Junction 28 and 29, the extent of which is outlined within the table below. The development is located in closer proximity to the A12 than Strategic Options 1 and 2 and is therefore likely to have a greater impact at Junction 12, while the impact at M25 Junction 29 may be less than Options 1 and 2. It should be noted that due to a lack of clarity on the flow diagrams in Appendix C, it has not been possible to calculate the increase at A12 Junction 12. It is recommended that this information is provided by BBC.